You are looking at the HTML representation of the XML format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query-continue>
    <alllinks galcontinue="Corteza_prefrontal_interna" />
  </query-continue>
  <query>
    <pages>
      <page ns="0" title="Comportamiento del consumidor" missing="" />
      <page ns="0" title="Comportamiento gregario del consumidor" missing="" />
      <page ns="0" title="Corteza orbitofrontal" missing="" />
      <page ns="0" title="Corteza prefrontal" missing="" />
      <page ns="0" title="Corteza prefrontal externa" missing="" />
      <page pageid="3" ns="0" title="Buyology" />
      <page pageid="97" ns="0" title="Construal Level Theory" />
      <page pageid="109" ns="0" title="Consumo, el imperio de los sentidos" />
      <page pageid="50" ns="0" title="Corteza frontal inferior" />
      <page pageid="40" ns="0" title="Corteza orbitofrontal interna" />
    </pages>
  </query>
</api>